Summary Of Significant Accounting Policies (Property And Equipment) (Details) (USD $)	12 Months Ended
Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Property, Plant and Equipment [Line Items]
Computer equipment	$ 93,326,000	$ 95,987,000
Office furniture and equipment	13,391,000	12,335,000
Leasehold improvements	54,972,000	43,957,000
Property and equipment, gross	161,689,000	152,279,000
Accumulated depreciation and amortization	(98,167,000)	(92,675,000)
Property and equipment, net	63,522,000	59,604,000
Depreciation and amortization expense	$ 22,300,000	$ 19,000,000	$ 16,600,000
Minimum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	2 years
Maximum [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, useful life	5 years

The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement.

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The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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- Definition

Gross amount of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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- Definition

Amount, net of accumulated depreciation, depletion and amortization, of long-lived physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

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